The Nocardiaceae are a family of aerobic, non-fastidious, high G+C, Gram-positiveactinomycetes that
are commonly found in soil and water.[1] Members
of this family have been isolated from Antarctic soils.[2]
Nocardiaceae present coccobacilli, filamentous or, rarely,
fragmented and palisading forms,[3] and
filamentous species grow in a branching morphological pattern
similar to fungal hyphae.[4]

Contents

Pathogenic
capacity

Some species colonize animals, and members of the Nocardia and Rhodococcus genera
can cause infection in humans and livestock.[5] Many
members of this family integrate mycolic acids into
their cell wall, and as
a result, Nocardia spp. may be mistaken for mycobacteria when viewed under a microscope
following an acid-fast stain.[6]

Environmental effects

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Wastewater
foaming

Nocardia species are often responsible for the
accumulation of foam that occurs in activated sludge during wastewater treatment.[4][7][8][9]
Biological foaming can be problematic for the water treatment
process, and foam accumulation is reduced by adding surfactants to
the wastewater.[10][11]

Bioremediation of
hydrocarbons

Soil Nocardiaceae can degrade hydrocarbons (e.g. petroleum distillates) and
have been proposed as bioremediation agents for environmental
spills.[12]

Nomenclature changes

In the 1980s, all Nocardiaceae species assigned to the Micropolyspora genus were
transferred to the genera Nocardia, Nonomuraea in family
Streptosporangiaceae, or Saccharopolyspora in family Pseudonocardiaceae.[13] This
effectively ended the official status of this genus, but the name
persists in older research articles.